Needless to say that Kaddish has always been
one of the most important parts of communal prayers (see Brachot 3a,
21b). However neither Talmud Bavli nor Yerushlami associates Kaddish with a
prayer intended to help the soul of the departed. Obviously there is nothing in
Kaddish that mentions anything about the departed. Still the idea of a Kaddish
recited by a Yatom definitely existed in the middle ages. In this short essay
we will try to explore the earliest sources for the notion that Kaddish Yatom
can help the soul of the deceased.

Bet Yosef on the Tur (Yore Deah 376) and
Rema (ibid) bring various sources that are based on the following story: a sage[1] meets
some suffering man who tells him that he is dead and that he was wicked during
lifetime. He will only be released from his suffering if his child will do
various meritorious deeds. In some versions this individual does not have a
child yet or is unsure if he has one, for when he died his wife was pregnant.
The sage goes into trouble to find the wife and wait for her to give birth (or he
finds a small child already, but that child is totally uneducated and wicked).
The sage then teaches the child words of Torah and how to pray. Later on the
child starts praying with congregation or teaches the Torah and the father comes
to the sage (presumably in a dream) and thanks him for salvation.

The
earliest three sources for this story that we still have are Masechet Kala
Rabbati (second perek), Tana Debei Eliyahu Zuta (17), and Zohar Hadash (Rut and
Parshat Achare Mot). Note that according to modern scholarship all three
sources were composed later than Babylonian Talmud and therefore are not from
Hazal but from Gaonic origin (Zohar Hadash may be even later). However much of
the material they contain probably existed in the times of Hazal. However none
of them except Zohar Hadash in Parshat Achare Mot mention Kaddish explicitly
(and even there Kadish is mentioned together with Haftorah[2] and
prayer). Some mention that the child said Barchu or blessings in a congregation;
others mention that he learned Torah.

Many
early authorities bring variant versions of this Agada: Ohr Zarua (50), Orchot
Chaim (Hilchot Avel), Kol Bo (114), Machzor Vitri (144), Rivash (115) and
Menorat Hamaor (Perek Gidul Banim; he brings it from Midrash Tanchuma,
Parshat Noach, but it’s not in our Tanchuma). Ohr Zarua actually
mentions the word “Kaddish” in this story but he also mentions Barchu. He
brings “Kaddish” in the name of Tana Debe Eliyahu (although in our Tana Debei
Eliyahu it’s not “Kaddish” but “Barchu” that is mentioned). Machzor Vitri and
Menorat Hamaor mention “Barchu”. Orchot Chaim, Kol Bo and Rivash mention both
Kaddish and Haftorah.

What
all of these versions of Agada have in common is that a son can save the
father’s sinful soul if he performs some acts of merit. It would seem that the
specific acts mentioned are the ones that a child could do[3].
Indeed the Rema (ibid) rules that it is even better for the soul of the
deceased that his son will be the Shliach Tzibur and this way he can add many
merits, not just the Kaddish.

So
where does the idea of Kaddish Yatom come from? It seems to me the main source
is Kitvey Arizal (Shaar Kavonot, Drushei Kaddish, 1). Indeed the
Sephardi mekubalim (e.g. Kaf Hachaim 55:20 and 132:17) understand Arizal
to imply that there is a specific Kaddish during every prayer called “Kaddish
Yatom[4]” that
is of greatest help to the soul of the departed[5].

Still
those Sephardi poskim who don’t usually lean towards Kabbala, agree with Rema.
For example, R. Ovadia Yosef writes (Yechave Daat 6:60, Yabia Omer Yore Deah
3:26) in the name of Yosef Ometz:

Kaddish
and Barchu is mainly for uneducated but learning Torah helps seven times more
than any prayer.

In
conclusion we would like to say that while Kaddish Yatom became the most
commonly associated[6]
Tikun for the dead, there are no early sources for this except Kitvey Arizal.
So is there a source that Kaddish related is related to elevating the soul of
the deceased? It depends on one’s opinion of Arizal[7]. For
those that think he had Ruach Hakodesh, indeed no other source is necessary.

[2]
R. Reuben Margolis interestingly states that the reason Haftorah specifically
is mentioned is because of the Nusach of the blessing after it that is similar
to Tziduk Hadin prayer during burial.

[3]
Indeed a child can read the Haftorah (see Mishna Megila 4:6) and according to
many opinions he can recite Kaddish as well (although some say that an adult
should say together with him).

[4]
In the Nusach Sepharadi it’s always the Kaddish before Alenu. It seems during
Shacharit this is the Kaddish Derabonan after Pitum Haketoret
(see Ben Ish Hai, Shana Rishona, Vayehi, 12 and Hagahot Ish Matzliach
to siman 132) but Piske Tshuvot (132, note 77) understood it to be the Kaddish
after Shir Shel Yom. Obviously in Nusach Ashkenaz, the Kaddish before
Alenu is Kaddish Titkabal that is said by the Hazan and therefore the Rema
brings the Kaddish Yatom to be the one after Alenu. During Mincha and
Aravit Sephardim always recite a psalm before Alenu and afterwards Kaddish
Yatom is recited, but no Kaddish is said after Alenu. Ashkenazim
don’t say any psalm and consistency consider the Kaddish after Alenu to be Kaddish
Yatom. As for the reason why this particular Kaddish helps the deceased
soul, the Arizal states that this Kaddish is in the lowest world of Assya.

It’s
possible that the author of Aruch Hashulchan did not see the exact quote from Kitvey
Arizal.

[6] In
the experience of present author with Jews from former Soviet Union, the
majority of questions coming from middle age Jews are about Kaddish and Yizkor.

[7]
Arizal is not the only authority who due to “Ruach Hakodesh” did not need to
bring any “proofs” from the Talmud. Sefer Hassidim and Sheelot Utshuvot Min
Hashamaim also bring no proofs for their rulings and are well quoted in
Halachic literature.